Motor fuel



. solvents and the like.

be added to gasoline with good results, as claimed- Patented Nov. 15, 1938 UNITED STATES PATENT OFFIC MOTOR. FUEL of Delaware No Drawing. ApplicationMay 28, 1935, Serial No. 23,860

6 Claims.

v The present invention relates to improvements in low boiling non-viscous hydrocarbon oils, such as naphtha and the like, particularly for use as motor fuels, and is a continuation in part of our application Serial No. 307,545 filed September 21, 1928, now Patent 2,004,094 issued June 11, 1935.

Hydrocarbon oils such as naphtha, which include gasoline, and particularly such naphthas as are made by decomposition of heavier oils and the like, often contain gum or gum-forming constituents which are objectionable in many respects. The exact nature of these objectionable impurities is at present unknown but gum content or more properly gum formation tendency is measured by the method No. 530.1 in the United States Bureau of Mines Technical Paper 323.B, entitled Specification for Petroleum Products and 'Methods of Testing, revised October 21, 1927, page 96. In brief, this method consists in placing cc. of the naphtha to be tested in a 3 inch diameter spun copper dish on a steam bath and evaporating off thevolatile material. The result is expressed in milligrams of gum left in the dish per 100 cc. of naphtha.

As noted above, naphthas containing relatively large quantities of gum are objectionable, particularly for motor fuels, cleaning naphtha, light It is also well known that on standing the gum content of many naphthas steadily increases.

The original application referred to discloses that the addition of certain organic materials to the naphtha, even though in very small quantities,

greatly reduces the amount of gum formed during storage as measured by the copper dish gum test and also prevents an increase of gum for prolonged, if not for indefinite, periods.v The materials disclosed as suitable for use as gum in hlbitors include aromatic hydrocarbons with condensed rings (polycyclic compounds) such as naphthalene, anthracene, phenanthrene and the like, and certain derivatives of these compounds having ,a'hydroxyl or amino group substituted in the alpha-position, such as alpha-naphthol and alpha-naphthylamine. These compounds are claimed broadly as gum inhibitors in co-pending application Serial No. 652,420 filed January 18, 1933 by Herbert G. M. Fischer as a division of the original' application 307,545. Phenyl alphanaphthylamine is also a suitable gum inhibitor, this being claimed in the original application 307,545. Mixtures of addition agents, such as alpha-naphthol and alpha-naphthylamine, may

in co-pending application Serial No. 675,330 filed June 10, 1933 by Fischer and Gustafson as a-continuation in part of the original application 307,545.

The present application relates to a low boiling hydrocarbon oil containing va small amount of gum inhibitor such as those mentioned above and also containing a small amount of volatile metal compound such as metal carbonyls and metallic organic substances which are useful for their antidetonation effects. Such anti-knock agents are (in themselves) well known in the art (see U. S. Patents 1,573,846, 1,575,443 and others).

Specific examples of anti-knock agents are the lead alkyl compounds, particularly lead tetraethyl, as well as others such as lead tetramethyl, lead triethyl, tin tetraethyl, bismuth triethyl and the like. Aromatic groups may be substituted in place of one or more of the alkyl groups in such compounds. g

The metal carbonyl compounds may be those of iron, nickel, or other metals, having anti-knock properties when used in low boiling hydrocarbon oils as motor fuels.

A typical example of the present invention is a motor fuel comprising gasoline containing 0.1 gram of alpha-naphthol per liter and containing from 1 to 3 cc. of lead tetraethyl per gallon. Other examples are given below.

The quantity of the gum inhibitor to be added is very small, not being greater in any case than 5 grams per liter of the naphtha and generally between the approximate limits of 0.01 to 1.0 gram per liter. There appears to be an optimum quantity .of the agent which will give the best results and it is a simple matter to make up samples of the difierent strengths and empirically select the most suitable concentration. As an illustration, the following example is given, alphanaphthol being added in difierentfquantities as indicated and opposite the number of milligrams of gum per 100 cc, of naphtha is given as determined by the above described test.

(lulu MaJIOO cc. Original naphtha. N aphtha' .5 r'. CmH1.0H/litre 2 relatively small quantities, for instance, between the approximate limits of 0.1 to 20.0 cc. per gallon of naphtha and usually between the limits of 0.5 to 6.0 cc. per gallon.

When metallo organic -antiknock agents such as lead tetraethyl are added to gasolines, they frequently cause increased gum formation or, in other words, act as a gum accelerator, particularly as measured by the copper dish gum test, and it has now been discovered. and is the chief feature of the present invention that the addition of a small amount of a gum inhibitor of the class described above to a low boiling hydrocarbon oil normally tending to form gum and containing a small amount of metallo'organic antiknock agent, effectively counteracts the gumaccelerating tendency of the metallo organic anti-knock agent. In fact it frequently reduces the copper' dish gum value to the same amount as it would in the same naphtha notcontaining the 'metallo organic anti-knock agent.

Metallo .organic anti-knock agents also frequently cause an increase in the rate of oxidation. This may be measured by the accelerated oxidation test which comprises placing 200 cc. of gasoline into a nickel-lined Emerson bomb (such as is used for making a B. t. u. determination), applying 200 lbs. of oxygen pressure and heating the bomb at open steam-bath temperathol per 1000 gallons of gasoline ture for 1- hour, cooling to room temperature and determining the porcelain dish gum value of the gasoline. It has been found that the materials hereinabove referred to as, gum inhibitors are also effective in either reducing the accelerated oxidation test value and/or preventing an increase thereof when a. metallo organic antiknock agent is added to the gasoline.

Table I sets forth experimental data showing the effect of a gum inhibitor of the type described and a metallo organic anti-knock agent, either singly or combined, on the copper dish gum value and accelerated oxidation test on a number of different gasolines, using 0.5 lb. of alpha-naphand using 3 A commercial gasoline obtained from Montreal.

A gasoline base stock obtained from Parkersburg. A gasoline base stock obtained from Parkersburg. A commercial gasoline obtained from Charleston, S. C. A commercial anti-knock naphtha. A gasoline base stock obtained from Parkersburg. Colombia naphtha cracking coil distillate. Logo aviation gasoline. Same as 17 but in closed bottles.

Table II sets forth experimental data showing the effect of several different amounts of alphanaphthol on the copper dish gum value of a fresh sample of low sulfur cracked gasoline both alone and with 1 and 2- cc. of lead tetraethyl per gallon.

Added as ethyl fluid.

The test results shown in Table II indicate that 0.1 gm. of alpha-naphthol per liter reduced the copper dish gum value to considerably below 20 mgs., (the satisfactory limit) in all three cases, i. e., both in the gasoline alone and in the gasoline containing 1 and 3 cc. of lead tetraethyl.

In other tests it has been found that in addition to reducing gum formation, these agents also reduce acid formation on standing and in one such test the original gasoline was found to have a gum test of 12277 mg./100 cc. after 3 weeks storage while a comparative sample which contained alpha-naphthol showed only 7.2 mg.

The acidity of the first sample was 28.95 as against 0.0 of the second after 3 weeks. The acidity is given in grams-of NaOH per barrel of oil and it should be noted that'both samples were of the same oil and both were neutral ,at

cc. of lead tetraethyl per gallonjof gasoline. the beginning of the test..

Table I On dish gum Accelerated oxidation test I Alpha- Alpha- Gaso- Alpha- Gaso- Alpba- No. line naphroot. $51 line naph- Pbeti 3 alone thol Phat alone thol PM 1 188 105 11 a 1 2s 57 20 a 29 9e 3 2 1 I 2 4.-. 40 200 7 n 12 268 7 n 26 107 10 2 4 6 7' 163' 200 a R 80 157 a 9. v 34 s 21 's 2 1 10.. 45 7 71 7 -22 12 16 11 11 37 .126 1a 1a 40 1 12 45 so 12 14 29 m 15 29 7 2 2 2 H 30 76 17 2o 17 1o 15 1s 10 21 13 2e .9 19 14 1a. s03 14 225 1a U 17 11 24 4 7 5 2 1s 14' 3 5 4 4 g Identification of gasolines'm Table I The present invention is not to be limited by any theory of the mechanism of the process not 1. M d-Continent cracking co distillate by any examples given-merely byway of illusa te 1. 5 1mm; 23.32% 2:31: SW96 U tratlon but only by the following clanns in which 4. Same as 3 but stored several weeks in vented bo t es. 5. Sameasiibut stored several weeks in closed bottles. 15 i 1-nteI.1t1on to plain! an novelty inheren a. Lego aviation gasoline. Y m the invent on. 7. Same as 6 but stored several weeks in vented bottles. We claim: 8. Same as 6 but stored several weeks in closed bottles. o. Aoommercial gasoline obtained from Montreal.' .1. A motor f el consistmg essen ially of s s0-' line containing constituents normally tending to deteriorate and form gum during storage, to which has been added about 0.01-1.11 grams per liter of a gum inhibitor consisting of an aromatic compound with a condensed hydrocarbon ring structure and a substituent selected from the class of hydroxyl and amino groups in the alpha position thereof, and about 0.5-6.0 cc. per gallon of a metallo-organic anti-knock agent having anti-detonation and other properties substantially equivalent to those of lead tetraethyl.

2. Motor fuel according to claim 1 containing alpha naphthol. r

3. Motor fuel according to claim 1 containing alpha naphthylamine.

4. A motor fuel consisting essentially of gasoline containing constituents normally tending to deteriorate and form gum during storage, to which has been added 0.01-1.0 grams per liter of alpha naphthol and 0.5-6.0 cc. per gallon of lead tetraethyl.

a 5. A motor fuel consisting essentially of gasoline containing constituents normally tending to deteriorate and form gum during storage, to which has been added 0.01-1.0 grams per liter of alpha naphthylamine and 0.5-6.0 cc. per gallon of lead tetraethyl.

6. The method of preventing gum formation and other deterioration of gasoline containing constituents normally tending to form gum during storage, to which has been added about 0.5-6.0cc. per gallon of a metallo-organic antiknock agenthaving anti-detonation and other properties substantially equivalent to those of lead tetraethyl, which comprises incorporating therein 0.011.0 grams per liter of a gum inhibitor consisting of an aromatic compound with a condensed hydrocarbon ring structure and substituent selected from the class'of hydroxyl and amino groups in the alpha. position thereof.

HERBERT G. M.- FISCHER. CLIFFORD E. GUSTAFSON. 

